The advantage of a "single payer" system would be to bring the benefits of large corporation negotiating power down to everyone. If there was no competition at

The advantage of a "single payer" system would be to bring the benefits of large corporation negotiating power down to everyone. If there was no competition at all, I'm sure that there is some potential for rising costs. But a lot of "single payer" systems actually do offer a fair bit of wiggle room for private market competition. The mess that is the state of the United States government health care really isn't a compelling argument here against single payer (the statistics for most of the rest of the world's health care systems, which are more integrated, kind of show this). I would expect that any "Medicaid / Medicare for all" system emerge in the United States would be two-tiered, like is the case in several other countries. To be honest, I would almost describe the situation in America as oligopoly-like in many cases (in insurance and hospital networks in particular) depending on where you are, and that would mute the effect of any corporate competition.